Good points. To answer I need to make a distinction between "going for winners" and "playing aggressively". You can play aggressively, either with pace, net rushes, angles, or variation, and still not go for winners in every shot. This is also something that the big 3 excels on (each in his own way), and most young players are not even capable to grasp the difference between this and "going for winners". The art of it consists in when, and how often, you go from "aggressive mode" to "winners mode".
My point is that if you want to be a top 5 player you must have a very solid "aggressive mode" to begin with, and obviously don go all the time to an inefificient "winners mode". There is a mental part to it that comes with experience, but the ability and talent to have a solid aggressive mode is not a mere question of experience.